I've been looking at many photos taken with z712 on flickr.com and most of the photos seem to be missing hair details. If you look closely at the pictures the hair seems to blend into a mess. I can't tell if the photos aren't on fine (as opposed to standard) and iso 100 where noise would be a minimum.
I've been comparing the photos to that of the panasonic z8 (closest thing out now to the z18). The z8 has plenty of chroma noise but in the photos I've seen seems to capture hair detail (at least the low iso shots do). While I like the photos Alan has posted I think iso 1600 would be unfair for any point and shoot. Hair, to me at least, has always been the real life test of resolution.